Pork butts (shoulder) are the easiest, and usually best cuts to smoke. Hard to screw up since they are so forgiving. Whole chickens are pretty easy as well. Briskets take a bit more care through the process, but if done right are by far the best product to come out of a smoker (IMHO). I know ribs are common, done by everyone, but I've had more trouble getting baby back ribs done well in my smoker. Used the 3-2-1, 2-2-1 methods, but still have issues through the years. I think I'm an oddity being able to do a full packer brisket better than ribs on a smoker...